Fichas
Cells and Organelles
Fichas del conjunto (26)
- 1What are prokaryotic organisms?Single-celled organisms
- 2What is a cell ultrastructure?A cell's organelles and the internal structure of most of them.
This can be examined using an electron microscope - 3Name the organelles found in plant cells, but not animal cellsCell wall with plasmodesmata
Vacuole
Chloroplasts - 4Describe the structure and function of the plasma membraneSTRUCTURE:
Mainly made of lipids and protein
Has receptor molecules
FUNCTION:
Found on the surface of animal cells and just inside the cell wall of plant cells and prokaryotic cells
Regulates movement of substances into or out of the cell
Receptor molecules allow it to respond to chemicals like hormones - 5Describe the structure and function of the cell wallSTRUCTURE:
A rigid structure that surrounds plant cells
Mainly made of the carbohydrate cellulose
FUNCTION:
Provide support for the cell by allowing it to become turgid
As water enters the vacuole by osmosis, the plant cell expands - the cell wall is strong enough to resist this expansion - 6Describe the structure and function of the nucleusSTRUCTURE:
Large organelle surrounded by nuclear envelope (double membrane), which contains many pores
Contains chromatin (made from DNA and proteins) and often a nucleolus
DNA contains instructions to make proteins
FUNCTION:
Controls the cell's activities (by controlling the transcription of DNA)
Pores allow substances (e.g. RNA) to move between nucleus and cytoplasm
Nucleolus makes ribosomes
- 7Describe the structure and function of the lysosomeSTRUCTURE:
A round organelle surrounded by a membrane, with no clear internal structure
Contains hydrolytic enzymes that digest material within the cell
FUNCTION:
Can be used to digest invading cells or break down worn out components of cell
Membrane prevents lysosome from digesting the cell itself - 8Describe the structure and function of the ribosomeSTRUCTURE:
A very small organelle, made up of one small sub-unit and one large sub-unit, that either floats free in the cytoplasm or is attached to the rough ER
Made up of proteins and RNA
80S = 20nm in diameter, found in eukaryotic cells
70S = slightly smaller than 80S, found in prokaryotic cells
FUNCTION:
Site where proteins are made (translation) - 9Describe the structure and function of the rough endoplasmic reticulum (RER)STRUCTURE:
A system of membranes enclosing a fluid-filled space
Surface is covered with ribosomes
FUNCTION:
Folds and processes proteins made at ribosomes
- 10Describe the structure and function of the smooth endoplasmic reticulum (SER)STRUCTURE:
No ribosomes
Large amounts located in cells that make lipids and steroids (e.g. liver and testis cells)
FUNCTION:
Makes cellular products e.g. hormones and lipids - 11Describe the structure and function of a vesicleSTRUCTURE:
Small fluid-filled sac in the cytoplasm, surrounded by a membrane
Some are formed by the Golgi apparatus or the ER, while others are formed at the cell surface
FUNCTION:
Transports substances in and out of the cell (via the plasma membrane) and between organelles - 12Describe the structure and function of the Golgi apparatusSTRUCTURE:
A group of fluid-filled, membrane-bound, flatted sacs
Small pieces of RER are pinched off at the ends to form small vesicles
Vesicles join and fuse together to make a Golgi apparatus
Vesicles are often seen at the edges of the sacs
FUNCTION:
Processes and packages new lipids and proteins
Makes lysosomes
- 13Describe the structure and function of the mitochondrionSTRUCTURE:
Usually oval-shaped
Has a double membrane - the inner one is folded to form cristae
Inside is the matrix, which contains enzymes involved in respiration
Found in large numbers in cells that are very active and require a lot of energy
FUNCTION:
The site of aerobic respiration, where ATP is produced
- 14Describe the structure and function of the chloroplastSTRUCTURE:
A small, flattened structure found in photosynthetic tissues of plants and some protoctists
Large starch grains form a temporary store for products of photosynthesis
Surrounded by double membrane
Thylakoid membranes inside the chloroplast are stacked up in some parts to form grana
Grana are linked together by lamellae - thin, flat pieces of thylakoid membrane
FUNCTION:
Site of photosynthesis
Some parts of photosynthesis occur in the grana, and other parts occur in the stroma (thick fluid found in chloroplasts)
- 15Describe the structure and function of the centrioleSTRUCTURE:
Small, hollow cylinders, made of microtubules (tiny protein cylinders)
Located just outside the nucleus in the centrosome
Found in animal cells, but only some plant cells
Wall of each centriole is made up of 9 triplets of microtubules arranged at an angle
FUNCTION:
Involved with the separation of chromosomes during cell division
Arrangement assists the movement of chromosomes
- 16Describe the structure and function of the ciliaSTRUCTURE:
Small, hair-like structures found on the surface membrane of some animal cells
In cross-section, they have an outer membrane and a ring of 9 pairs of protein microtubules inside, with a single pair of microtubules in the middle
FUNCTION:
Microtubules allow the cilia to move
This movement is used by the cell to move substances along the cell surface - 17Describe the structure and function of the flagella (undulipodia)STRUCTURE:
Flagella on eukaryotic cells are like cilia but longer
They stick out from the cell surface and are surrounded by the plasma membrane
Inside they are like cilia - two microtubules in the center and 9 pairs around the edge
FUNCTION:
Microtubules contract to make the flagellum move
Used like outboard motors to propel cells forward - 18How are organelles involved in protein production?1. Proteins are made at the ribosomes
(the ribosomes on the RER make proteins that are excreted or attached to the cell membrane, whereas the free ribosomes in the cytoplasm make proteins that stay in the cytoplasm)
2. New proteins produced at the RER are folded and processed (e.g. sugar chains are added) in the RER
3. They are transported from the RER to the Golgi apparatus in vesicles
4. At the Golgi apparatus, the proteins may undergo further processing (e.g. sugar chains trimmed or more added)
5. Proteins enter vesicles to be transported around the cell (e.g. glycoproteins move to the cell surface and are secreted)
- 19What are the four main functions of the cytoskeleton?1. Microtubules and microfilaments support the cell's organelles, keeping them in position
2. Help to strengthen the cell and maintain its shape
3. Responsible for the transport of organelles and materials within the cell
4. The proteins of the cytoskeleton can cause the cell to move - 20Compare the size of prokaryotic cells and eukaryotic cellsPROKARYOTIC = extremely small (less than 2µm diameter)
EUKARYOTIC = larger cells (about 10-100µm diameter) - 21Compare the DNA of prokaryotic cells and eukaryotic cellsPROKARYOTIC = circular DNA
EUKARYOTIC = linear DNA - 22Compare the cell wall of prokaryotic cells and eukaryotic cellsPROKARYOTIC = cell wall made of polysaccharide
EUKARYOTIC = no cell wall (in animals), cellulose cell wall (in plants), or chitin cell wall (in fungi) - 23Compare the organelles of prokaryotic cells and eukaryotic cellsPROKARYOTIC = few organelles and no membrane-bound organelles (e.g. mitochondria)
EUKARYOTIC = many organelles and other membrane-bound organelles present - 24Compare the flagella of prokaryotic cells and eukaryotic cellsPROKARYOTIC = flagella (when present) made of the protein flagellin, arranged in a helix
EUKARYOTIC = flagella (when present) made of microtubules, arranged in a '9+2' formation - 25Compare the ribosomes of prokaryotic cells and eukaryotic cellsPROKARYOTIC = small ribosomes (20nm or less)
EUKARYOTIC = larger ribosomes (over 20nm) - 26Why can't normal microscopes see the internal structure of bacterial cells?Prokaryotes like bacteria are roughly a tenth the size of eukaryotic cells.
Normal microscopes aren't powerful enough to look at their internal structure
Información
- Descripción
- El usuario ha eliminado su información de asignaturas Fichas sobre Cells and Organelles, creado por Usuario eliminado el 05/03/2018.
- Creado por
- Usuario eliminado · mar 2018
- Actualizado
- 5 mar 2018
- Visitas
- 91
- Historial
-
- Creado por Yinka F · 23 ene 2018
- Copiado por Yinka F · 5 mar 2018
- Valoración